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The resonant-mass gravitational wave detector SCHENBERG is a spherical detector that will operate with a central frequency around 3200 Hz with a bandwidth of 100 to 200 Hz. It has a spherical mass that works as an antenna that weighs 1150 kg and is connected to the outer environment by a suspension system designed to attenuate local noise due to seismic as well as other sources of vibration. The sphere is suspended by its center of mass. When a gravitational wave passes by the detector, the antenna is expected to vibrate; this motion is monitored by six parametric microwave transducers whose output signals are digitally analyzed. In order to determine the detector performance better, it is necessary to obtain the vibration frequencies of the sphere with a better precision. To achieve such a goal the sphere with the holes to mount the transducers and the central hole from which the sphere is suspended is simulated in a finite element method program when the gravity is applied to the sphere and the deformation is kept. After that the vibration normal modes of the sphere are calculated and they are compared to the experimental results. After that the gravity is misaligned with the suspension of the sphere to simulate the effects of it, then the simulation is done again and no differences were found. [ABSTRACT FROM AUTHOR]

Interferometric gravitational wave detectors (IGWD) are very complex detectors, the need for locking the detector in a dark fringe condition besides the vibrations that affect the mirrors is very difficult challenge, creating the need for active suspension systems. These active systems make the system reach the desired sensitivity but make the calibration of such detectors much more difficult. To solve this problem a calibrator is proposed, a resonant mass gravitational wave detector could be used to detect the same signal in a narrower band and use the measured amplitude to calibrate the IGWD, as resonant mass gravitational wave detectors are easily calibrated. The main challenge in this design is the operational frequency of the calibrator, these massive detectors usually were built in frequencies close to 1 kHz but the frequency of the Gravitational Waves detected is around 100 Hz, then the design should adapt to this. This work aims to design and simulate a suspension of the mechanical antenna of such a calibrator. The suspension is modelled in finite elements method and a design of such a suspension is presented as its normal vibration modes. [ABSTRACT FROM AUTHOR]

This work shows the optimization process of a quadrupole mass at high-speed rotation using the finite element modeling (FEM). Such a mass should compose a gravitational signal generator device, which is intended to use in an experiment to measure the speed of gravity. The device must produce a tidal gravitational signal with a frequency of 3200 Hz. The gravitational wave detector Mario Schenberg is the first option as the detector of the signal. The previous steps of the project are briefly discussed, and the FEM simulations for the quadrupole mass are shown. An analysis of the mechanical stresses produced at high-speed rotation is presented. The most successful FEM simulation yields a favorable geometry for the inclusion of the magnetic suspension of the quadrupole mass. The results indicate the feasibility for the continuation of the project and subsequent construction of the real device. [ABSTRACT FROM AUTHOR]